Propelling screw for motor sleighs



Jan. ;27, 1931. F w l,790,035

PROPELLING SCREW FOR MOTOR SLEIGHS Filed July 18, 1928 I I I b az / VGNTa I? Patented Jan; 27, 1931 FRnNz wELs, 'or HOHENELBE, ozrcHosLovAKIA; Assreivoaor {ONE HALF TO C RIS- v TIAN KENIG, or HARTER, NEAR rrorrnvnrnn, CZECHOSLOVAKIA EROPELLING SCREW FOR MOTOR sLEIGHs This invention relates to improvements in propellingscrews for vehicles, suchas sleighs' or'sledges, motor cars andthe like..

*It has already been proposed to drive motor-sledges or sleighsby means of screws pro- Vided with a square thread or with a' thread disposed vertically with respect of the bodyof the screw. However sledges or sleighs furnished with a screw ;of this kind have not proved satisfactory for the reason hereinafter set forth. v d i According to' the present invention the sieigh-or sledge screw is proviaed ,With

'screw-thread, in which 'the efi'ective screw surface is inclined 'with respect tofthe body v I of the -screw,` preferabiy at degreem In the accompanyingv drawingsis shown A diagrammatically and by way ofexample, in

Fig. la sledge screw constructed according to the present nventon.

Fg. 2 llustrates n sde vew a motor sledge provided with an Operating screw according to Fig. l.

According to the present invention, there is provided a sledge-screwin which 'the pressure side ofthe screw-thread is inclned with respect to the body of the screw. The most favonrable an le of incination is %5 de'rees.

The thrust-trajectores'of the whole screw, which preferably-is-made of a single piece v and is forced down onto the ground by its weight or by a spring or the'like, pass in the direction of the arrow c, so that the snow, ice

293313', and' in A stria August e, -1927. wardand backward, thethread may be undercut as shown; in dotted hn'es in Fg. "1.

Theiend of the screw-face maybe sharp edged.

The screw-drive according to the present inventon: is suited for road-sledges, s1eighs,'

and sledges or ;sleighs ofany kind used for traveliing on sledgy or sandy gronnd.

Figz illustratesdiagrammatcally a sledge K according to the present invention, 'in which the screw'shaft s unversally connected to the drivingshaft by a universal joint d in order teper-:nit the siedge tojtravel over ronghor' nneven' surfaces.- e Iclaimza v body and' a screw-thread on the body and the rearand frontiaces ofthe screw-thread. be-

inginclined;downwardly in the direction of r travel. i

2; A propel'lng* screw for Operating on snow and ice incrusted surfaces comprising a v body, a screws-thread on the body the effective i screw surface of the thread being inclined with respect to thebody and thescrew thread also being ;undercut, snbstantially as descrbed. V I t In testnnony whereo'f I afix my signature RANZ WELS.: e

or the like is not pushed away or scraped ofi?,

but is compressed and forms an inclined surface of tghtened or compressed snow or'ce',

which acts as a bear-'ing orrest for the screw for moving forward the vehicle without any' slip worth mentioning. i v i The ground or the lateral parts of the ground are not pushed away or scraped off 'neither on starting nor during drving, be-

cause at its forward ,end or at both of its ends the diameter of the screw is gradually reduced and thus gradually forms' a screw-` threaded track, which is subsequently engaged and deepened bythe not reduced part v of the screw, whereby the sledge is driven forward.

In order that the 'vehicle can travel for- 1. A "propelling iscrew for Operating on snoW and -ice 'incrusted-surfaces including a 

